English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

LAMOST DR5 released more than 200,000 low resolution spectra of early-typestars with S/N>50. Searching for metallic-line (Am) stars in such a largedatabase and study of their statistical properties are presented in this paper.Six machine learning algorithms were experimented with using known Am spectra,and both the empirical criteria method(Hou et al. 2015) and the MKCLASSpackage(Gray et al. 2016) were also investigated. Comparing their performance,the random forest (RF) algorithm won, not only because RF has high successfulrate but also it can derives and ranks features. Then the RF was applied to theearly type stars of DR5, and 15,269 Am candidates were picked out. Manualidentification was conducted based on the spectral features derived from the RFalgorithm and verified by experts. After manual identification, 9,372 Am starsand 1,131 Ap candidates were compiled into a catalog. Statistical studies wereconducted including temperature distribution, space distribution, and infraredphotometry. The spectral types of Am stars are mainly between F0 and A4 with apeak around A7, which is similar to previous works. With the Gaia distances, wecalculated the vertical height Z from the Galactic plane for each Am star. Thedistribution of Z suggests that the incidence rate of Am stars shows adescending gradient with increasing jZj. On the other hand, Am stars do notshow a noteworthy pattern in the infrared band. As wavelength gets longer, theinfrared excess of Am stars decreases, until little or no excess in W1 and W2bands.

Metallic-Line Stars Identified from Low Resolution Spectra of LAMOST DR5